Voice of Music Amp - VM 160

[The Dude]

Part question- part suggestion: Looking at your first post, I notice the chassis of the amp doesn't sit all the way back or flush with the rear of the cabinet. I'm attaching a picture to show the area I'm talking about. See the red dot. If you cut that board under the chasssis to allow the whole chassis to go back a bit so the face plate meets the rear of the cabinet, would that give you enough room for your new speaker? I obviously can't know without measuring, but it could be an option if it will work.



In other words, cut off that piece of wood on this line so that the chassis is further away from the speaker. Maybe that gets you enough room?

[Enzo]

Or get one of those plug in solid state rectifiers, they are short. If all that is in the way is the recto tube...

[Chuck H]

And maybe find a way to touch up the paint loss (from cleaning?) of the VM logo

[olddawg]

Or get one of those plug in solid state rectifiers, they are short. If all that is in the way is the recto tube...

Might also raise the B+ a bit and you may like the amp better. A couple of diodes soldered under the socket would be cheaper.

[tigerzilly]

So you live and learn.

Glad you like the circuit changes.

I learned that the old speaker sounds pretty damn good! And yes I do like the circuit change. Thanks for taking the time to provide a revised schematic!

I had a friend over today and I recorded him playing through the VM. He was loving the tone. Here are some clips.

[tigerzilly]

Here's Tom playing the VM 160. I really like this amp. A total score!

[Chuck H]

Yep. That's what I remember about my VOM build. It's remarkable how much audible LF and HF in the "right" ranges for guitar just leap out considering what a small OT it seems to be for the wattage. Like a bell chiming while you have a little water undulating in your ears I've considered sending my VOM OT to a magnetics shop to have it torn down and reverse engineered! I still have it, so there's time to decide. Sounds great.

EDIT: Just to add... The OD/clipping tone on my build was very good as well. Thick and middy with a hint of that shiny top end and the nice low end but never farty or harsh. But that's running at the stock PT voltage which is only about 300Vp on the 6V6 tubes. Just a really great combination, that OT with a pair of 6V6's at the lower voltage. It really knocked my socks off.

[Sweaty_Meerkat]

tigerzilly How much does the amp weigh, including the cabinet? Someone else told me 8lbs, but that just seems way to low!

[tigerzilly]

tigerzilly How much does the amp weigh, including the cabinet? Someone else told me 8lbs, but that just seems way to low!

It's not very heavy. Eight to ten pounds could be right. I sold it a while back so I can't weigh it now.

[eman-blues]

Hey Folks,
I've got the same Voice of Music 160 amp mentioned in this thread. The power transformer is burned up. Any idea what the specs are and where to get a replacement?
Thanks!
-E

[loudthud]

What are the dimensions of the four screws that hold the transformer ? Should be something like 2.00 x 2.50 inches or 2.25 x 2.88 inches.

A 360-0-360 secondary means the filter capacitor has to withstand 500V surges when the amp is turned on. These days finding a multi-section filter cap that can survive that kind of abuse is not so easy. It might be wiser to get a 280-0-280 secondary and use solid state diodes and a 450V rated cap. The B+ will be about the same 400V.

[mozz]

A lot of F&T caps are rated for 500v, easy to obtain, priced right.

[eman-blues]

Look like the screws that hold the transformer are 2 1/2" x 3 1/8 ". As for the caps, I don't care about looks or original restoration... just function. So I'd be ok to put electrolytics inside the chassis vs. find a cap can that matches.

[loudthud]

I looked through the Hammond website and anything that is close like 290BBX or 273DZ have 2.25 x 2.813 screw pattern. I only looked at "Z" mount types like the original VOM transformer. If you are willing to try to squeeze an upright transformer in there, you should be able to find something close to the original.

360-0-360 @ 100mA, 5V @ 2A, 6.3V @ 2A

[eman-blues]

Thanks for the tips. I'll have to study that. I'm a bit of a newbie to this stuff.
Thanks!
-E